SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a0b9bc22776e66bfb560c6d994d6d7f5295d5da625775bdefe0ebdd330987ce' 
  AND token = 'WeYCZ4AdmuYzteTaaC9UXhyBiP0cl0h/kZTeLlV0bC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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