SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c5aaa157326d466626f4333d421722500f26f137bbffb6a1d4f9a74269334ed' 
  AND token = 'nOtackJ1OaxpZ3jk14ciXZO2yPXUZyVk/axLnKNa11o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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