SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '118ef560f04e03a250d76d8d0f4d43a3b912306c77d653ed7572b790c6cf6765' 
  AND token = 'mFYrvpAp0tzUxhSEA/CI/FfvDGg+WMfSYjbiSiJm4Do=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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