SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ea4a6587510e013c979c3735784fe02edbaedbecb4109368b13354073e152c1' 
  AND token = 'iwsGhSKjTUnVg4TJSuy1qifvsscl8cDBOdrI/8a1nAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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