SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef00397c283e0d3356f08b6d29f31ba1aa74a0c2cf1e980b0e3bb6712483dbd1' 
  AND token = 'OF6lkx+pHn+bt/C4GCUlO/KauwdJpaVxJN2vVseI+vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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