SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcc8b955bfc04ee11b2906d8ac3a12baab1bc9cc9ed79ccba10e15ffd1b47055' 
  AND token = 'of3EIEkFevStXdqk0cEEVn5+Z3BPjHxSzif42AS+8d8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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