SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7a1ec5b186d53d6e97fe676446c7408758c591c47ad40bf363580537beacf043' 
  AND token = 'huw9M8Euqp1GQB1zQktQv0G4r86Zuc9hCYXwXG09T4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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