SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '212e7c4651d1099d0c7d9221c0d668da3a11e2cb87b652276eda940a378f71c0' 
  AND token = 'DyGfMTLNCMwLTZcYuzFlu4GIfcwlHkMENG6gNWNcq+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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