SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a76a007ab1b24ab8468707b1fa2201657ebb9bba4b30b32b552876df1f0f894' 
  AND token = 'TI8cAFVSzq4m38kGjSO/YFNl/CZSf6HJqQ/rUjYXu1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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