SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '530b5eba7be36aa6e51312c9c91c163653984dca49d97994e486a8ee22fbe306' 
  AND token = 'l9ROAMDiFIl9I18faD2ArzKMWESKB0V7nrJvTYaKd4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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