SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ac1d56829e63ef978d153fd9d0e37b1a993a50eada2e85d051283b4945c398e' 
  AND token = 'c6OixJPnu8l0jFx/a3HonmcNtmcjsvS2/72AUno8za4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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