SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8bb88f7f6a1d611aca5041829b6499c70deb20a8f371217f882ec8dad774e9b' 
  AND token = 'EWetgP3CmwJGb9X1cqu2r6FEG+EkOVVrifZ/cJMsvjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}