SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03bad13e5d00dda1e6a08c0544bb8946d94b1a486b6586fcb0c0046396a02d2b' 
  AND token = 'lu+VofgMBxCcH8xuTtizBkeOE+Jmvysw3WTLjazTASM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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