SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '51282faa02e3db779692f9e4fb38babaf1400bc7ae6cdef106e3955bcb64eedb' 
  AND token = 'Gf7z/8t2n74G8v5bv0qLSJWoTbpnPZjJkqKVkpHY++s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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