SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73463ceaf6502bb399bdc93392ff6a95918551b276d799f46b54c045b2ba3040' 
  AND token = 'ohbAsALFTeqSIga73kvQcXyNLhVXLM5b6ESO7KbQ2X0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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