SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e6bbf8bb3b8119c976f6ee80822490f212db0a19833c6824cf84d4ce6162ca2c' 
  AND token = 'SDlj8A732DK4hKasfRJB8LFr+LiRpVY1vJVchGvw4E4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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