SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2a66065570eb692677bf335bcbb187e9307ac7dc9e45865227f8d409b27dfc4' 
  AND token = 'JRu4Ff95KU9vuc/UvS5feuC/uAAHlTdRLXv1BpPCHfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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