SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7754192114c6657a4b186950700c8f8786cb55605cf92b4be7d57842e77fdf2' 
  AND token = 'R7BZb9FpzzXKm5VzYTv49FujVhePgx31UL7cYl06j+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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