SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92253674d8515d87d7e749340fe740b431f72567197288ad064a327c301c4f67' 
  AND token = 'f+CqX3oFjy0i3BGtMKfDHiHU/ynZF2wJldKr6DDQ7iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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