SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91408b61ca83fcf5708074fcffb3a878890c6ce6c737b36db98c19b7bc07decf' 
  AND token = 'owk/jlKNsFWmvoj3EBgLW2k6V0VavHfOAi3B0pjXRCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}