SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e30fc3fb815c82f2b12771dafcce71a0fbb9f56c803b9ea42a81350200b083a3' 
  AND token = 'Z3X0g09D5gVNwUKOxrW5q/EZBgoJOBLt6szhQPrbIXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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