SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57aaf58277b92c5dc51e47eef36a53dff2c27864f461217c298170269a803681' 
  AND token = '7Uqgj3YzVFf798uMxaGzyq2CIwfiRMyfFZ+mz8KTIkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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