SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd08b18385c6bb638e932bead0cf1d51bfeca271ac5280193e16525038125507f' 
  AND token = 'g+xM9kg9ne+YAmewcOLXzQETxpaEmCZwT7hhNLR/v34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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