SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8cc0a2d9e7104e1806df2f58add33547a0b03e82ee08a4acd7b14f5cbbeff1d' 
  AND token = 'AoAHnHSEYkqp8v37dCWJKwRGBqya7/QJuUJHiocz8Os=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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