SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3989b115d048e401fa2c6782e2e2ea4a2b5ab55c6b3ce06fdf444c1908dc954' 
  AND token = '2HX2kMQqZpVy87MdjUP2nqF4snEazpN+3nXHXWroYw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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