SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bd4f5be190125f440facdfeceec6df3fac604598046441772d824a7390406cd' 
  AND token = 'ILP4CpUNJKTlB/L7m+mQ+x9eSRLYsor/BxjrbMzWsaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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