SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d69664e925a8789fd75dfc946c56530d8bc2116fbd5d4d0ecf06c2128e40fc2' 
  AND token = 'ylsrBvxXzXzWP5SO5PFiOidpQhOKpBFNLVH7zK/E+wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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