SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f551c8900f48eab517f7ff38b8974eda4372810b1059c2696a678cb4d8439edd' 
  AND token = 'YNr1oyWIOFhqLp2z4jgzKw2g0LO8eQvCXpyTPG/FGfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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