SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aab5b64c79984a64daca0c6d082a4c3c792ec1dad26ac70d68f4d70aa0e6b2b' 
  AND token = 'CSMeyvgH2qI2H3f9iygPtBEmQeYmikAliY5DyGnthD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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