SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf083b37aa6a4ff370cf5873fe4b760939d313dbc1d10964c9e136f5e08cd1d0' 
  AND token = 'Q1btEbYV9RE0w3HODYQj428ddxdU4dd8y9Rz2SoRWUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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