SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6244059a17ed73ab0dd8713ac616028e88fb732d6ad435360454868307c796a6' 
  AND token = 'CBiHccHHENilRPwO/F8LB+YYgXGMKUJAaH9W+u1Cyfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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