SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4430493505c8e01acd907f5b805f0b5fee7d0d229c68b557f7761a3c6a93a4f' 
  AND token = 'P2ges3ktedbLO27xLoxbr31m43CdVVd8ASrC7HoW9B0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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