SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd09ae0b20bec1226cf5735b4f5cd5798415147e4d82a4351f730087b4fdd21f9' 
  AND token = 'nOYjTfKCljz50PAZoFw741Omi1x4AcAiX6zxBdtawc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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