SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '109851efac8853d95a857b7b01d3e0177f4465675aabcda0bd41e82cb07a769a' 
  AND token = 'UHMCsjONRBZq12gXxP1v/9HdcTlSNBmfbB0X9L4k2qE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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