SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4c9356b6578959f03257249d2cb9c0472a4b61c8901d3a98b501009fdf40691' 
  AND token = 'Qg3rzOXWGEl/UxzjLhcWzQAZ/zGHybhOUcoysmEqNvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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