SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aa993a811126fa93ce1a4b0f21ffd581855686fdc3f28f0d70ba71a5fb0d4729' 
  AND token = 'aMGoNXJ8Jx1aHvyMC+rSBqZ3s2xVutaY1bKzbn/1XWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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