SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95d9b1d6e108d186eaedc35a659a3eb4b45c064e1e27a5aaeb3b88aa605bbb4d' 
  AND token = 'SSz978byOoRFh3Cd5gLQWGMJvqAqaq3ntGiPVi4hntE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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