SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fda0b18c606e70d3ca53f73dd5bf9fe5a0a3253722412f306e9cd9d620c056bd' 
  AND token = 'MlkI3bP1WHXYfP+gbhcMgbYvZfgFVf/T2mEATvLoVjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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