SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '188dd1818538d4261d5658ddcee853a80f046949c0150fa1227515b4beccd96b' 
  AND token = 'gBrAiIDxY13+Xxt6Qzur1WVoVA++sDUK3UHFUCXIjV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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