SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f0b8d1d7c58f767f496dff364b82f9805d7b4b4493bc2ca13c38a642d755f2e' 
  AND token = 'KcaT8/CfZKPKAbqcXYMDr7vLLGNv/mcRLpQqaxOWuAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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