SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fb1b039964c645e529e8e5fdf7c78fb48f002f04edc896652183b8a4994d76e' 
  AND token = 'Y2m8ku+WbeFYuEcu+XcV5M3l1Iu/mypJoGvDMQEA/No=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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