SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'acc7cd9ad2ceb9a684cbf3c06d7c94c7b20c3045b412251a67120a8ba44f2acc' 
  AND token = 'nt637nnao1cz4Nwi9ojKPeWo26AT7aL/Slr4AhivOdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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