SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97516fb8a7658b22bfd5adfaf4bb065ac5aa1a97ea3005ea5d897676c671d59b' 
  AND token = '1rR/VRzzP/ipRRVnVEZzEOoFKS08aNTsHRQMjY8qrEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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