SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3ed1b34dd84486fc750b50182783091cdcc5240fa5f4abc3f5139aeeeb4290c' 
  AND token = '3DIrOviaMsJKgcp8I7cVWz9SZLE2alCoB3tBSoR2a14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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