SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45506ad96e1d05600ce6b2e0c986438a09661a1233ac42b91ff544133d863113' 
  AND token = 'ge3VLvgrs6sBNwO8guOi7bUxyeXQwYGVE5JxquDWEkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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