SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d37ea2f1942afb5718285de279d7f9f9ce1f9bea3f9c704df753f14aba5836b' 
  AND token = 'uDlr46ATAWkFV15SN7Kx/xZ9XRFhvmyO1fjv38TvgeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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