SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '742bcd7417eb562e545f9b702dbdb06c502394a1856ff7b11ac1425e2baf1c70' 
  AND token = '0ng+YUZjR8//BMUCQCFQcNhbKfxPBAnNJ3evURT8YYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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