SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bd785ab188587f085d387994f29cceb59b1ffea9e4e856b249d5de508ab2809' 
  AND token = 'R3G7yq4dvvZ+ukE/BPmhhrU4bwkd7dzKBW+jYG6WhsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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