SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f5331a6e60cf06a0fea5342c86684a6522fdcceea557620ce67207fed7afefb' 
  AND token = 'ykNkU+7DffC0MAsps+dGZWefDeHK5YgwRNTkmfqVaTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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