SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2ca412fcde40423d13cd5d1c2fe8411774d13055ef2604a479676ab8f090d14' 
  AND token = 'qpbSK9b45FenQApYBYtJUmYAJ0GORiw/oRfouqULCJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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