SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94f66cdad84d82a24d05ab05cf04dfb3a69a713b5be4baa41d87b93dcfec7375' 
  AND token = 'bRMg8RVp4Q7kzPXD/JMOxFKwgqPzeoJuGNOn+ZjnvGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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