SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7857550ffb1ae77243b0a419d51386fb4af3d881f91685c1c04deefefc5398d2' 
  AND token = 'YO6HxV5msddOiBm6NwuD2wOmKi1M8Eknn8IvF/FNk/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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