SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1289f227da4820e34089b1bf8bf0e4589160031e4b54a53e70d419129f9e0440' 
  AND token = 'Gwr31eH3wID9KIfpo9YSPEWfVr/uGSvLjo0A+ohvI0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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