SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63a9a9d6aa571b24422f6f4089c812c450a4b80f0ac56587b68df7574143d55a' 
  AND token = 'WuV/UFctvaQlsPlROCUhZzHivVK45JqEN7dWtmRpTZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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