SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f82312c048073f83bbc6b7e5aa11d15645f954d53919034041379274893c5cde' 
  AND token = 'HfLmj7V1RpW+xv94qDuXImgwM/goim/Uy0h8wbyY9/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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