SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0bd9e29acd37a8968caa0784ea09791368fff39b413bd5d744696f448659cf8' 
  AND token = 'mpLVdaZ8domgwLUkBiDkiLwjzG0K3XKkEXmROFq1jy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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