SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9365db84bd3f526d94f5d4462d103fac1d530899bad04e2307023201d357973c' 
  AND token = '5bI4LUq/gXaTFHTmXG4h/e5i0XOBz4/LoBFzsa9YqVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}