SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e6e3145337cb04925ab1f8fd7e6e8a3dbcbab8fbd263b4f9c177c57c085a918' 
  AND token = 'mi6iw3ynuZcQvJSVJUyA3FTG4kzFNSnfjeAuYaUPwkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}