SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e5da87b64b4d9ad94d2d7f065c61440b34bdfcfac9ec3effcba66cbacb13e63' 
  AND token = 'Fv5Cs2r03O8E+ukDMmX30kJIcHtVQzXFf5YYAdMXwB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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