SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05e8fda270361958e14b1e560942f9e67794bc63a558ef8685c5d9165cf993df' 
  AND token = 'RFVqgTsY5ylvRwaDxeObwoH1v37FyGzhxkNkBIulPgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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