SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a90ab1f6f17df9229431339cd14e3a0794f3fe38e38f7862058473e65121036' 
  AND token = 'R+ULw8lfUkPaYY98XLSgG4U2NRNgEYP2TJ/TlOO3hkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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