SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97e7d14a7797d9aef366af4594453c08671f8a9d4acd973ca58ff551966eb6cf' 
  AND token = '0TuORUUHcmuGLwCPDzioQL2gteZic8kdU1rKC7Roi9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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