SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2a3c6fcb7b89571cb883b2cd8d350a8977cfdc2906ac1bc16dd99cd2dd66e818' 
  AND token = 'fIFKlP2wFqvQphZakJMFdrqfzT3tWAQztgmuM5drUTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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