SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '76061e83ee23af29b7ddabee85b36b6196c48a4ca43195c171872e366ba0e86a' 
  AND token = 'yTYVrRfR1zotkO7GkWycZSFjoO20FrBM2efWIqzCvQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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