SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5a554869853f7f8b2fc6db5d8c45b8969cd0acc8ab33ec646ede923ad1dd409' 
  AND token = 'Vuv5+mUvuTGK/jRY7jB0Pm5PdpLLJd0sWK7/jU3gbwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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