SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb5735b95700f6250c21d393d7bf4f52e1a7a82373db638db2026722907155fd' 
  AND token = '6xfzbYKvC+Cd7gdmRuTqXXOhfo8vCKZoe4FdHfqDcDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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