SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bc4a714facce1971e6ae972c1ad47242bc4f655c2b87df7387ebdd0990ed148' 
  AND token = 'PPBpKYbgO3WNzsXk4NzgJD3kbOlkEGXMC68WnKW0QVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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