SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2a4ee587c9ddcbc9958598befa6752cdd20e6f6840608e9bf6de9a79234ae90c' 
  AND token = 'SKxEL/pbBbAplyHpsHBvhk1FeG6NrAnM0D7GeUUcuEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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