SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d25fe1a158a7a19306df1d7139c7ad4caf62502cf9666a0e197b7e53ee59685' 
  AND token = 'CtJBCTYzbbMVLlTPexA78JSlHxhya3Tfyyca9mfIIDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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