SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63a2a652b434533a7cbd6725368a370eb12d0a2734087895dbc665646096086a' 
  AND token = 'Q/2a47Rzs326YEE+0bxz+Y02gdzHd2ReCGM44hEZXcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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