SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ea38400d7ad62a3393d15d1e1994c2978729bfa1786e96748b178c66fae259bb' 
  AND token = 'HkJc24V4J7DKOkEUofqS9dvyhRJPmczVw9j5d/v3/XY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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