SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e262f006ae6ccead9a7255b215354a3b4801b89dac5708b274e3a990d0360bc' 
  AND token = 'tqa8pVUx+nFtTOJKgRhYp0c1nbUKhw/p4zTe1hWvWmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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