SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '174f5bae097cd20b37c59f625610a71100f6b18daa1a7f5ee754033a1006e46b' 
  AND token = 'eE67AyZdJgtc6aFltKkmcsof/989bzStxAYJuCgnmJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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