SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95a0327cbcd3c0c58445cc58bf2f5ff235d73dfaef5daffddda7eb02c665bb59' 
  AND token = '5kl0V3pnxN6WggKSjfICAmyjHTWLsjaJkVE3+CfDfXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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