SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1eb104ae8704a6da9d71ec92b0de1ece4f8b8d61dc29bcb8e13e179688351ba' 
  AND token = 'sDJMLISnZkrVMBJGAqIeZVAdPrJcR+oYaId3aFvnigU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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